Westminster Council has approved plans to build a 27m high zinc and glass ultra-modernist extension to the Royal College of Art (RCA).

The move will anger architectural conservatives, as they claim the oval-shaped Ellipse has no space among listed buildings – the Royal Albert Hall (RHA) is only yards away – in the National Conservation Area in Kensington Gore.

The building is designed by Nicholas Grimshaw & Partners and the submission of the plans follows 18 months of consultation with Westminster City Council, English Heritage and local residents.

David Elliott, chief executive of RHA, has announced he will write to the Government Office for London, urging John Prescott to block the decision.

The proposed £27m building has caused anger among residents in the area, who claim it will block historic views of the RHA and Hyde Park.

Last year, 90 per cent of people polled at the Proms opposed the plans and well-known critics of the scheme include Odeon cinema co-owner, Robert Tchenguiz.

RCA claims the complaints regarding the aesthetic threats to the RAH are unfounded. It said that the elliptical form of the building ‘complements the curves of the RHA’, while retaining the ‘integrity of the Grade 2-listed Darwin building’.

Sir Christopher Frayling, rector of the RCA, said: “We are delighted that Westminster Council has been so positive about our new building.

“The approval will enable us to provide new exhibition galleries, giving the public much greater access to the work of the College,” he said.

Funding for the building will primarily come from the private sector.

Building work is due to start in the summer of 2005 and is to be completed by the spring of 2007. Details: www.rca.ac.uk